This project concerns the effects of marihuana (tetrahydrocannabinol) on reproductive function. Rhesus monkeys are administered acute or chronic doses of tetrahydrocannabinol, and reproductive hormones (FSH, LH, estrogen and progesterone) are measured. The study includes an evaluation of the doses necessary to produce any alterations in reproductive hormones, the duration of the effects, and the time course of the reversibility of the effects. BIBLIOGRAPHIC REFERENCES: Smith, C.G., Moore, C.E., Besch, N.F. and Besch, P.K. Effect of Delta-9-Tetrahydrocannabinol (THC) on the secretion of the male sex hormones in the Rhesus monkey. The Pharmacologist 18(2):738, 1976. Besch, N.F., Besch, P.K., Moore, C.E. and Smith, C.G. The effect of marihuana (delta-9 tetrahydrocannabinol) on the secretion of Luteinizing hormone in the mature female Rhesus monkey. Clinical Chemistry 22:1189, 1976.